So would you agree that the University is most likely out of line charging me £50 as an admin fine and that I'd have a leg to stand on should I attempt to claim it back?

Hello all, Last term I incurred a fine from Loughborough University because I got muddled up with the dates of the direct debit for my tuition fees and accommodation. The direct debit was returned as unpaid by my bank and therefore I had to pay the University directly a couple of days later. For this "inconvenience" to them they have issued a fine of £50 as an 'administration fee'. I've been thinking about the matter and it seems similar to the case of bank charges that people are claiming back all the time as the fines are disproportionate to the amount of inconvenience cause. I'm pretty sure that I haven't put the University out by £50 just by accidentaly bouncing a DD. In fact i'd be surprised if it cost the University anything at all. The University will not allow me to graduate if this fine is unpaid. So i'm in abit of a dilemma as I can't really afford to pay the fine. If anyone could advise me on this matter i'd be extremely grateful. Thank you